High aspect ratio wastewater system

ABSTRACT

A leaching conduit comprising: a high aspect ratio channel; a first pipe in fluid communication with the high aspect ratio channel; and where the aspect ratio of the high aspect channel is configured to allow for aerobic conditions in and around the leaching conduit. A wastewater system comprising: a processing tank; a leaching conduit in fluid communication with a dosing device; wherein the leaching conduit comprises: a high aspect ratio channel; a dosing pipe in fluid communication with the high aspect ratio channel; and where the aspect ratio of the high aspect channel is configured to allow for aerobic conditions in and around the leaching conduit. A high aspect ratio form comprising: an open bottomed and open topped generally rectangular container comprising: a first end wall; a front wall adjoining the first end wall with the top of the front wall and the top first end wall being generally coplanar; a rear wall adjoining the first end wall; a second end wall adjoining the front wall and the rear wall having a first height with the top of the second end wall, the top of the front wall, and the top of the rear wall being generally coplanar; a plurality of interior walls having a second height, and the plurality of interior walls adjoin the front wall and the rear wall with the tops of the interior walls, front wall and rear wall being generally coplanar; at least one lifting member attached at least one of the following: the first end wall, the front wall, the rear wall, the second end wall; and where the interior walls are configured to form at least one volume of a first width, and at least one volume of a second width, and wherein the first width corresponds to a width of a geonet volume and the second width corresponds to a width of a granular volume. A cover for a high aspect ratio form comprising: a cover configured to fit onto a high aspect ratio form; a plurality of openings in the cover configured to not cover a plurality of granular volumes in the high aspect ratio form.

CROSS-REFERENCES

This is a continuation-in-part of a patent application by David A.Potts, entitled “Low Aspect Ratio Wastewater System”, application Ser.No. 11/144,968 filed on Jun. 3, 2005, the entire contents of which arefully incorporated by reference herein.

TECHNICAL FIELD

The present invention relates to leach fields and aerobic treatment ofwastewater within soil, and more particularly to a high aspect ratiowastewater system and leaching conduit.

BACKGROUND

Known leaching conduits, such as arch shape cross section molded plasticchambers, or stone filled trenches with perforated pipe, used fordomestic and commercial wastewater systems provide interior void space,based on the thinking that a buffer space or flow equalization is thusprovided for variations of inflow of wastewater. The sidewalls ofconduits, where they interface with the surrounding soil, are alsocommonly conceived as providing surface area for percolation ofwastewater, in addition to the bottom surface of the conduit. A familiarcrushed stone filled trench, having a modest (4 inch) diameterperforated pipe running along its length may have about 50% void space.Currently, arch shape cross-section molded plastic leaching chambershave entirely open interiors, open bottoms and sloped and perforatedsidewalls. A common cross section shape for each typical conduit has awidth of about 30 to 36 inches and a height of about 12 to 18 inches.Thus this conduit may have from about 12 inches to about 18 inches ofwater depth at any one time. It has been seen that in these prior artconduits, a biomat will often form on the bottom and sides of theconduit, thereby lessening the effectiveness of the leaching conduits toproperly infiltrate the wastewater into the soil. Drip irrigation linesare usually approximately one half inch in diameter and are typicallyburied 12 to 6 inches below grade.

Leaching conduits are typically covered with 6 to 12 inches or more ofsoil, for several reasons. One is to protect the conduits from damage.Another is to prevent contact of humans and animals with potentiallydeleterious microorganisms associated with the wastewater being treated.Still another is to prevent odors. The dimensions of the conduitsdiscussed in the preceding paragraph would lead to the fact that thebottom surface of the conduits are typically at about 24 inches or morebelow the soil surface.

Generally, it is an aim to have aerobic treatment of the wastewater inthe soil. Current thinking with prior art systems is that there is anair-soil gas interchange, so that oxygen is continuously supplied to thesoil, to enable good microbiological treatment. However, the soil depthsat which prior art conduits operate are disadvantaged in this respect.Since the bottom surface of the conduits are typically about 18 to 24inches below the soil surface, the bottom surfaces of the conduits areoften in an anaerobic condition since the oxygen demand exceeds theoxygen supply. One improvement with such systems is to force airserially through the conduit and soil influence zone which surrounds theconduit, as described in U.S. Pat. No. 6,485,647 to David Potts, issuedon Nov. 26, 2002, and which is incorporated herein by reference in itsentirety.

Therefore, a wastewater system is needed that provides for greateraerobic conditions in leaching conduits, thereby allowing for greaterprocessing of the wastewater prior and during absorption into the soil.

SUMMARY

The disclosed invention relates to a leaching conduit comprising: a highaspect ratio channel; a first pipe in fluid communication with the highaspect ratio channel; and where the aspect ratio of the high aspectchannel is configured to allow for aerobic conditions in and around theleaching conduit.

The disclosed invention also relates to a wastewater system comprising:a processing tank; a leaching conduit in fluid communication with adosing device; wherein the leaching conduit comprises: a high aspectratio channel; a dosing pipe in fluid communication with the high aspectratio channel; and where the aspect ratio of the high aspect channel isconfigured to allow for aerobic conditions in and around the leachingconduit.

The disclosed invention, in addition, relates to a high aspect ratioform comprising: an open bottomed and open topped generally rectangularcontainer comprising: a first end wall; a front wall adjoining the firstend wall with the top of the front wall and the top first end wall beinggenerally coplanar; a rear wall adjoining the first end wall; a secondend wall adjoining the front wall and the rear wall having a firstheight with the top of the second end wall, the top of the front wall,and the top of the rear wall being generally coplanar; a plurality ofinterior walls having a second height, and the plurality of interiorwalls adjoin the front wall and the rear wall with the tops of theinterior walls, front wall and rear wall being generally coplanar; atleast one lifting member attached at least one of the following: thefirst end wall, the front wall, the rear wall, the second end wall; andwhere the interior walls are configured to form at least one volume of afirst width, and at least one volume of a second width, and wherein thefirst width corresponds to a width of a geonet volume and the secondwidth corresponds to a width of a granular volume.

The invention, additionally, relates to a cover for a high aspect ratioform comprising: a cover configured to fit onto a high aspect ratioform; a plurality of openings in the cover configured to not cover aplurality of granular volumes in the high aspect ratio form.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure will be better understood by those skilled in thepertinent art by referencing the accompanying drawings, where likeelements are numbered alike in the several figures, in which:

FIG. 1 is a cross-sectional view of a disclosed low aspect ratioleaching conduit;

FIG. 2 is a perspective view of a geonet;

FIG. 3 a front view of the geonet from FIG. 2;

FIG. 4 is a front view of another embodiment of the disclosed geonet:

FIG. 5 is a front view of another embodiment of the disclosed geonet;

FIG. 6 is an exploded view of one embodiment of a dosing pipe;

FIG. 7 is a side view of the dosing pipe of FIG. 6;

FIG. 8 is a cross-sectional view of the dosing pipe of FIG. 7;

FIG. 9 is a schematic of a disclosed low aspect ratio wastewatertreatment system;

FIG. 10 is a cross-sectional view of a disclosed alternative to ageonet;

FIG. 11 is another embodiment of the disclosed leaching conduit;

FIG. 12 is another embodiment of the disclosed leaching conduit;

FIG. 13 is a perspective view of a disclosed high aspect conduit;

FIG. 14 is a cross-sectional view of the disclosed high aspect conduitfrom FIG. 13;

FIG. 15 is a cross-sectional view of another embodiment of the disclosedhigh aspect conduit;

FIG. 16 is a perspective view of another embodiment of the disclosedhigh aspect conduit;

FIG. 17 is a top view of the disclosed high aspect conduit from FIG. 16;

FIG. 18 is a cross-sectional view of the high aspect conduit from FIG.16;

FIG. 19 is a top view of another embodiment of the high aspect conduit;

FIG. 20 is a side view of the high aspect conduit from FIG. 19;

FIG. 21 is a perspective view of a high aspect conduit form and cover;

FIG. 22 is a top view of the high aspect conduit form from FIG. 21;

FIG. 23 is a side view of the high aspect conduit form from FIG. 21; and

FIG. 24 is a cross-sectional view of another disclosed conduit.

DETAILED DESCRIPTION Low Aspect Ratio Conduit

In the present invention, as illustrated by the FIGS. 1 through 12,conduit 20 has a much lower aspect ratio (height divided by width) thanconduits in the prior art. Thus, the bottom of the conduit can bepositioned closer to the surface of the soil. And, it is an option toinstall a leaching system by laying a multiplicity of conduits 20 on thesoil grade and to then cover them with appropriately chosen media and/orsoil. This approach is especially advantageous for leaching system siteshaving shallow depths of native soil, such as those which overlie a highwater table or ledge, and the like. The disclosed conduits may beinstalled in spaced apart rows, or in segments which are spaced apart,all interconnected by suitable distribution lines. In the following, oneconduit segment or length is described.

In one embodiment, shown in FIG. 1, the disclosed conduit 20 comprises aperforated dosing pipe 22 which overlies a low aspect channel 24 all ofwhich lie beneath a soil surface 30. The low aspect channel 24 isapproximately rectangular shaped in this cross-sectional view. The pipe22 distributes the wastewater relatively evenly along the length of thechannel 24. A dosing pipe will typically be of a small diameter, forinstance from about ¾ to about 2 inch in diameter. The pipe has suitablesmall spaced apart openings along its length, which openings may besmaller near its water source and larger farther away. A geotextileshroud 26 drapes over the pipe 22, so it runs downwardly and laterallyoutward, onto the top surface of low aspect channel 24. The shroudextends to the outer edges of the channel 24, to keep soil frominfiltrating vertically down into the voids of the channel 24. Theshroud provides assurance that there will be good water flow path fromthe pipe perforations and underside of the pipe, to the top of thechannel 24. Optionally, some crushed stone, or plastic pieces or othergranular or permeable media, may be placed in the space 28 under theshroud 26, near the pipe 22. With reference to FIG. 1, in oneembodiment, the top of the low aspect channel 24 may be consideredessentially planar, because as shown in the end view of FIG. 1, theshroud width “wS”, that is the width of the base of the vaguelytriangular cross section which comprises the region defined by thesloping surfaces of the shroud 26 is a small fraction of the channelwidth “wC”. Alternatively, the shroud 26 may be a preformed shapepermeable material, such as perforated molded plastic. In anothervariation, the shroud may be impermeable when used with blower systemsand since the preponderance of the top of the channel 24 will bepermeable. If a blower is in fluid communication with the low aspectratio channel, the blower may be configured to intermittently blow airand/or some other gas through the channel 24 in order to assist indrying out the adjacent soil and to prevent biological buildup.Additionally, the blower may be configured to provide oxygen to theconduit and assist in dissipating water into the soil. The blower mayalso be configured to keep the dosing pipe and perforations fromclogging with organic matter. The blower may dissipate water from thesoil such that it prevents freezing around the conduit. The entireconduit can also be made of crushed stone, or plastic pieces or othergranular or permeable media in substitution for the “geonet”. This istrue with both the low aspect channel and high aspect channel describedbelow.

The low aspect channel may have a geonet 40 located within it. Thegeonet 40 may be obtained from various manufacturers, such as, but notlimited to: Enkadrain drainage system product No. 9120 from ColbondInc., P.O. Box 1057, Enka, N.C. 28728; and the several geonets namedGrasspave2, Gravelpave2, Rainstore2, Slopetame2, Draincore2, Surefoot4,Rainstore3 from Invisible Structures, Inc., 1600 Jackson Street, Suite310, Golden, Colo. 80401, and Advanedge® flat pipe from AdvancedDrainage Systems, Inc. 4640 Trueman Boulevard, Hilliard, Ohio 43026.Referring now to FIG. 2, a perspective view of a geonet 40 is shown. Thegeonet 40 is typically comprised of an irregularly coiled stringystructure 44 contained between one or two layers of air-permeablesheeting 48, which layers may feel to the touch like thin felt, andwhich is commonly and generically called geotextile. In one embodiment,the geonet 40 has only one layer and one side of the layer has theirregularly coiled string plastic structure, as shown in FIG. 2 and FIG.3 which is a side view of the geonet 40. The low aspect channel 24,comprising the geonet 40, may have an estimated void volume of about90%.

In one embodiment, the low aspect channel 24 will have a thickness, orheight “h” as shown in FIG. 1, of about ¾ inch. The channel width“w_(c)”, or lateral dimension of the channel 24 may be about 12 to about48 inches, and preferably about 12 to about 40 inches. Optionally,geotextile may be placed at the opposing side of the vertical edges ofthe channel 24, to stop potential ingress of soil. In use, wastewaterintroduced into the low aspect channel 24 will percolate into the soilin the downward direction primarily, to a lesser extent in the sidewaysdirections owing to the small vertical edge dimension, and also in theupward direction, when the conduit is full. Since the top of the conduitis permeable to air, there is good microbiological functioning of theleaching system, since air from the soil between the channel 24 and thesurface can diffuse into the channel 24. If a geonet is used which hasboth a top and a bottom layer of air and water-permeable sheeting 48,such as the geonet 52 shown in FIG. 4, the local portion of the toplayer in vicinity of the pipe 22 may be removed, and the shroud 26 needonly extend laterally a small distance from the pipe 22.

In alternate embodiments, the low aspect channel may be deeper than apreferred geonet material. In that case, one or more geonet mats may belaid on top of the other, such as shown in FIG. 5, where two geonet mats40 are laid on top of one another, with the irregularly coiled stringyplastic structure 44 facing each other. In another embodiment, thegeonet mats may be fabricated with a greater thickness, e.g., about 2inches, about 3 inches or about 6 inches in thickness. In embodimentswith thicker geonet mats, it may be practical to omit the dosing pipeand allow the wastewater to flow through the void space of the mat, froma low aspect channel end or selected injection points.

The aspect ratio of the low aspect channel 24 may be less than about6/30 (6 units of height divided by 30 units of width, or about 0.2),preferably the aspect ratio will less than about 1/10 (1 unit of heightdivided by 10 unites of width, or about 0.1), and more preferably theaspect ratio will about 1/30 (1 unit of height divided by 30 unites ofwidth, or about 0.033) to about 1/36 (1 unit of height divided by 36unites of width, or about 0.028) or less. These ratios reflect only thedimensions of the channel 24, and not the dosing pipe 22. However,inasmuch as the preferred dosing pipe 22 is small in diameter andvertical dimension, the ratios are roughly applicable to the whole ofthe conduit as well.

In other embodiments, the low aspect channel 24 may be much wider thanshown; and, it may comprise a continuous wide layer beneath the soilsurface 30. Spaced channels 24 (also called laterals or branches),following the traditional leach field layout may be utilized in anotherembodiment.

In one embodiment, the perforated pipe 22 will be about 4 to 12 inchesbeneath the surface of the soil 30. Thus, in that embodiment, the bottomof the low aspect channel 24 will be about 5-17 inches deep, dependingon the diameter of pipe 22 (if a pipe 22 is used in the embodiment).Thus, it is feasible in many soil areas to have the conduit wholly inthe generally more permeable A-horizon of the soil. Since mostwastewater will percolate downwardly into the soil beneath the lowaspect channel 24, the wastewater will be better treated than if thebottom of the conduit was deeper. The soil nearer the surface has betterchance of being maintained or restored to aerobic condition by naturaldiffusion processes within the soil. In another embodiment, there willonly be one perforation in the pipe 22 about every 10 to 20 feet.

In another embodiment, pipe 22 may be inside the confines of low aspectchannel 24. Solid distribution pipes with a manifold may be used with orwithout dosing pipes 22 to get relatively even water delivery to thechannel 24. Typically dosing will be carried out with a pump and thusthe pipe 22 need only be of small diameter, as previously indicated.Dosing may also be accomplished with a dosing siphon or an accumulatortank with an actuated valve. In another embodiment, dosing pipe 22 maybe sandwiched between two channels 24, an upper channel and a lowerchannel. In another embodiment, when a dosing pipe is sandwiched betweentwo layers, the top geonet layer may have an impermeable sheeting overit to serve to dissipate the water velocity. In still anotherembodiment, the pipe 22 may be located between 2 approximatelyhorizontally parallel low aspect channels 24.

FIG. 6 shows another embodiment of the perforated dosing pipe 22. Inthis embodiment, the dosing pipe comprises a perforated tube 72,perforations 73 in the tube 72, and a slotted sleeve 76. Theperforations 73 of the tube 72 lay along a length of the pipe that isapproximately equal to the length of the low aspect channel 24, thatlength is referred to as LLAC. The sleeve length is also approximatelyequal to the length of the low aspect channel 24. In another embodiment,the slotted sleeve 76 may be relatively short segments located adjacentto a perforation on the tube 72. For instance, in an embodiment with oneperforation about every 15 feet of tube 72, there may be a sleeve 76 ofabout 6 inches located adjacent to every perforation. FIG. 7 shows thesleeve 76 fitted over the tube 72. FIG. 8 shows a cross-sectional viewthrough the tube 72 and sleeve 76 through plane A-A. The dotted arrowsshow possible paths for the water leaving the perforations, andtraveling between the sleeve and the tube and exiting pipe 22 at theslotted area 80. This configuration of a perforated dosing pipe 22 isadvantageous in that water will not spray out of the perforations andimmediately impact the soil surrounding the conduit 20. This preventserosion of the soil around the conduit 20. Thus, in this configuration,the dosing pipe 22, allows water to be directed only towards the lowaspect channel 24, rather than to the surrounding soil. In thisembodiment, a geotextile shroud 26 may be omitted, and a filler mediumsuch as, but not limited to stone, pebble may be used to prevent soilfrom entering the geonet. It should be obvious to one of ordinary skillthat the perforations 73, may comprise multiple perforations locatedalong the length of the tube, or there may be only one perforation pertube 72, or one perforation 73 per a certain length of tube 72.

While dosing with a pump is preferred for uniformity of distribution,the pipe 22 may be configured to rely on gravity to distribute thewastewater. In such case a larger pipe, up to about 4 inches indiameter, may be used. In still another embodiment, for either a gravityor a pump system, the pipe 22 may be eliminated, and water may bedelivered directly into one end of the channel 24, or into the middle ofthe channel 24.

The disclosed conduit 20 will provide less interior storage volume, orbuffering void space, than prevalent prior art chambers or prior artstone filled trenches. Therefore, depending on the particular flowhandling requirements, a water handling system may be used. For example,as illustrated by FIG. 9, a flow equalization tank 56 receives dischargefrom a processing vessel 60, such as a septic tank. Sewage flows from adischarge source 64 to the processing vessel 60. The discharge source 64may be, but is not limited to: a residence or a business. Periodically,a dosing device, such as, but not limited to a pump 68 will flow waterfrom the flow equalization tank 56 to the conduit 20 located in thesubsurface leach field. The conduit 20 comprises a dosing pipe 22 and alow aspect channel 24. FIG. 6 shows one embodiment of a wastewaterscheme. In other embodiments, the flow equalization tank 56 may beomitted, and the PROCESSING VESSEL 60 may be used for flow equalization.This may be facilitated through the use of a pump to control levels inthe primary processing tank.

In use, the conduit 20 will be periodically dosed with wastewateraccording to the particular soil's hydraulic conductivity, preferablywith loading rates of about 0.25 to about 3 inch per unit horizontalbottom surface area. Preferably, the time between dosing will about twotimes the time for a dose of water to percolate into the soil. It isconceived that that will better enable the low aspect channel 24 andrecently-saturated soil near the low aspect channel to drain of water,and to refill with gas, which is in good part oxygen containing air,flowing downward through the soil and through the permeable top of theconduit. If air distribution pipes are connected to vents, the foregoingeffect can be enhanced by suitable valving at the inlet end of the pipeor pipes, through the use of check valves on the vent lines, whichvalves will close when water is applied to the conduit. When the waterpercolates into the soil, it allows the check valve or similarfunctioning device to open and provide for the flow of air to replace anequal volume of water.

When using a low aspect channel 24 as described in this patentapplication, the vertical dimension (h) may be about one inch. Aone-inch high low aspect channel will only hold one-inch depth of water.So, the ratio of volume to area is 1 to 1. This low ratio of volume toarea arises from the present invention's low aspect ratio and isadvantageous in that it prevents anaerobic conditions from developingsuch that a biomat layer is formed on the bottom surface of the channel24. Therefore, smaller doses of anaerobic water and organisms enter theinfluence zone. The influence zone is that zone where waste water islargely renovated, or biochemically converted into a moreenvironmentally benign form, prior to re-introduction into the groundwater. This prevention of anaerobic conditions encourages a stable andsustainable aerobic microbial community to be present on a continuingbasis thereby providing for greater treatment of the wastewater. Thisalso results in a greater long term acceptance rate of wastewater at agreater percolation rate.

Thus for any given daily flow of water, the flow must be dosed out tothe channel in an amount that does not overflow the conduit, that is,the amount of water must be no more than the volume containable by theconduit at any one time. For instance, if the conduit has 4 rows of 20foot channels, that are each 1 inch high and ˜10 inches wide, and theconduit is filled either with a geonet or other medium thereby allowinga void space of about 95%, then the total instant capacity for thatconduit is given by the following:20 feet(length)×12 inches/foot×1 inch(h)×10 inches(w)×4 rows×95%=9120in³.Thus, wastewater from the source 64 should be dosed out in increments ofno more than about 9120 in³ at a time, to prevent over-flowing of thechannel 24. If the conduit appears to be overflowing, despite limitingthe increment of water to a proper amount, then this may be anindication that there is a malfunction such as, but not limited to ablockage in the system.

In one embodiment of the disclosed conduit, the height of low aspectchannel is about 3 inches or less, and preferably about 1 inch or less.Correspondingly, the ratio of volume to bottom surface area is about 3to 1 and less, preferably about 1 to 1 and less.

Other plastic products which function similarly to a geonet may be used,so long as there is a substantial void between top and bottom layers.For example, a molded plastic three dimensional grid may be used. FIG.10 shows another alternative. The geonet may be replaced by granularmedia 68, such as crushed stone or pea stone, captured between twolayers of air and water permeable sheeting 48, such as a geotextile. Inanother alternative, polystyrene aggregate incorporated into suitablenetting or blanket may be used. For example, the type of polystyreneaggregate associated with the commercial product EZflow Drainage Systemsmay be used. EZflow drainage systems are manufactured by RING IndustrialGroup, LP, 65 Industrial Park, Oakland, Tenn. 38060. When soilconditions are favorable, and there is not a great risk of upwardlymoving fine grained material from the underlying soil, it might beacceptable to eliminate the bottom geotextile layer in any embodiment ofthe invention.

FIG. 11 shows another embodiment of the disclosed conduit. In thisembodiment, the low aspect channel 24 has a width w_(c). However, thegeonet 40 has a width that is greater than w_(c), such that when thegeonet 40 is placed in the channel 24, two sides 84 of the geonet 40bend up or down along the sides of the channel 24. After the channel 24is dug, and the geonet 40 is placed in the channel, then a perforateddosing pipe 22 may be located on top of the geonet 40, with a geotextileshroud 26 over the pipe 22. Then, soil is filled in to the soil surface30. In this embodiment, the channel 24 is no longer mostly rectangularshaped in cross-section, but is approximately “U” shaped incross-section.

FIG. 12 shows another embodiment of the disclosed conduit. In thisembodiment, the low aspect channel 88 may be curved as shown. An air andwater permeable sheeting 48, such as a geotextile material, may belocated on the boundaries of the channel 88 and around the dosing pipe22. The conduit may have a geonet located within it.

While it is an advantage to be able to put the conduit of the inventionnear the surface 30 and atmospheric oxygen, in some climates freezing ofthe soil and water in the conduit could be a risk. There is the obviouschoice to install the system deeper. Another choice, which also mayinvolve compromise with respect to vertical gas interchange, is to placean insulation layer within the soil, above the conduit. For instance, acellular plastic insulation board can be installed. The board mayinhibit the desired vertical gas interchange, so it may be providedselectively with through holes, to enable soil gas flow. Morepreferably, the insulation will be air permeable media which nonethelessprovides better insulation that soil. For instance, pellets of plasticor perlite may be provided, as well as polystyrene aggregate, mentionedabove. If the conduit is comprised of closed cell aggregate, and not ageonet, then the aggregate itself will provide the conduit withself-insulation, which will inhibit the cooling and freezing, at leastin the bottom portion. A blower can also be utilized to provide forincreased drainage during subfreezing conditions.

A geogrid is typically a product that is used to stabilize soil tovehicle loads, etc and is typically a square mesh that gets buried abovethe strata requiring stabilization. The disclosed low aspect ratioconduit may have a geogrid installed between the conduit and the soilsurface to protect the conduit from wheel loads.

The disclosed leaching system is more likely to have aerobic conditionsdue to its low aspect ratio and its low maximum volume to bottom surfaceratio of the conduit, thus leading to better processing of thewastewater. The disclosed system also provides for wastewater processingnear the soil surface, which provides for greater access to oxygen and agreater likelihood of aerobic conditions for the processing.Furthermore, as septic fill becomes increasingly scarce and moreexpensive, the low aspect ratio leaching conduit minimizes the need andquantity of fill required. Additionally, air may be flowed through theconduit to optimize aerobic conditions.

High Aspect Ratio Conduit

On occasion there may not be enough space to install a low aspect ratiowastewater system as described above. Therefore, this applicationdiscloses a low aspect ratio wastewater system that may be thought of asbeing turned on its side, thereby creating a high aspect ratio conduit,wherein the void space is relatively small, and the top of the conduitis relatively close to the surface 30 ground. Referring to FIG. 13, anembodiment of a high aspect conduit 92 is shown. A perforated dosingpipe 22 is shown under a ground surface 30. The perforations 96 areshown located intermittently on the dosing pipe. The dosing pipe 22 isshown with a cap 100 on one end. An air and water permeable sheeting 48encloses a portion of the perforated dosing pipe 22. The generallyrectangular volume beneath the dosing pipe 22, also enclosed by the airpermeable sheeting 48, contains a geonet 40. The generally rectangularshaped volume 41 is also know as the channel of the conduit 92. That isthe conduit 92 comprises a channel 41 where wastewater flows through,and gas infiltrates into. Additionally, since the conduit 92 has a highaspect ratio, then the channel 41 also has a high aspect ratio. Itshould be noted that wherever in this patent application a geonet isreferenced, that geonet may be replaced by a granular material. Thedosing pipe 22 is configured to deliver fluid via the perforations 96down into the geonet 40.

FIG. 14 shows a cross-sectional view of the conduit 92. The dosing pipe22 is surrounded by an air permeable sheeting 48. Additionally, in thisview, the irregularly coiled stringy structure 44 of the geonet 40 canbe seen under the dosing pipe 22, and surrounded by the air and waterpermeable sheeting 48. The height “h” of the channel 41 is shown in FIG.14, and the width “w” of the conduit is also shown. The aspect ratio isgiven by:Aspect Ratio=h÷w  Eq. 1Thus it can be seen that the aspect ratio for this disclosed conduit 92is much higher than the conduit shown in FIG. 1. However, this disclosedconduit 92 will take up less land surface area (acreage) than a lowaspect ratio conduit configured to treat generally the same amount offluid and thus will be useful when surface area is not readilyavailable. In some embodiments, the width of the conduit is about 3inches or less, and more particularly between about 0.5 and 2 incheswide. The height of the conduit is between about 48 inches and about 6inches, and more particularly about 12 to about 40 inches. Thus, in thisdocument a high aspect ratio will be about 96 to about 3, and moreparticularly between about 80 and 6. In other embodiments, the highaspect channels may be “Z” shaped for additional surface area. Thebottom surface area of the conduit is relatively small when compared tothe sides of the conduit. The heavier sludge may settle to the bottom ofthe conduit and leave the sides relatively free of blockages, therebyallowing for a greater infiltration along the side of the conduit ascompared to the bottom of the conduit. Additionally, the sides of theconduit have more oxygen since they are closer to the surface.

FIG. 15 shows a cross-sectional view of a another embodiment of thedisclosed high aspect conduit 104. In this conduit 104 there are aplurality of perforated dosing pipes 22, each wrapped in a air and waterpermeable sheeting 48. Additionally, each dosing pipe has a generallyrectangular volume beneath each dosing pipe 48. Each generallyrectangular volume contains a geonet 40. The irregularly coiled stringystructure 44 that makes up the geonet 40 is shown in this view. Eachgeonet 40 is enclosed in an air and water permeable sheeting 48. Eachdosing pipe 22 is configured to deliver fluid via perforations 96 (notseen in this view) into the geonet 40. FIG. 15 shows three dosing pipes22, however, other embodiments may have as few as 1 dosing pipe and upto as many dosing pipes as practical in a given area of land. The highaspect conduits 92, 104 disclosed in FIG. 14 and FIG. 15 could bealternatively constructed by installing a dosing pipe 22, with a geonet44 wrapped around the pipe 22, in the center of an air and waterpermeable sheeting 48 that is about 2 feet wide and folding the sheetingin half about the pipe. A difference in this alternative is that thecore material would be wrapped around the pipe too. Also, the bottom 93of the high aspect conduits 92 and the bottoms 105 of the high aspectconduits 104 may be constructed without an air and water permeablesheeting 48, that is the bottoms 93, 105 may be open to the surroundingsoil. All the channels 41 can also be made of crushed stone, or plasticpieces or other granular or permeable media in substitution for the“geonet”.

FIG. 16 shows a perspective view of another embodiment of a disclosedhigh aspect conduit 108. In this embodiment, three perforated dosingpipes 116, 120, 124 are shown, however it should be understood thatfewer or more dosing pipes may be used as necessary to properly treat anamount of wastewater. Beneath the center dosing pipe 120, is a generallyrectangular volume 112 of geonet 40. This volume 112 generally extendsand runs along a plane that is collinear to the center dosing pipe 120.A volume of 128 of geonet 40 is located under dosing pipe 116 and ispartially adjacent to the geonet volume 112. The geonet volume 128 maybe thought of as a generally rectangular volume formed into a “U” shape,with the bottom of the “U” 132 being adjacent to the volume 112 ofgeonet. There are a plurality of geonet volumes 128 located under thedosing pipe 116. Similarly, there are plurality of “U” shaped volumes128 of geonet located under the dosing pipe 124, with each volume 128having the bottom of the “U” 132 located adjacent to the geonet volume112. The irregularly coiled stringy structure 44 that make up the geonet40 are not shown in this Figure in order to simplify the Figure forbetter understanding. The dosing pipe 116 is configured to deliver fluidto each of the geonet volumes 128 located beneath it via perforationsconfigured to line up with each geonet volume 128. Similarly the dosingpipe 124 is configured to deliver fluid to each of the geonet volumes128 located beneath it via perforations configured to line up with eachgeonet volume 128. The dosing pipe 120 is configured to deliver fluid tothe geonet volume 112. Additionally, each of the dosing pipes 116, 120,124 are covered with an air and water permeable sheeting (not shown inthis view for ease of understanding), and each of the geonet volumes112, and 128 are enclosed in an air and water permeable sheeting (notshown in this view for ease of understanding). In one embodiment, thewidth (w) of the conduit 108 may be about 3 feet, and length (l) of thechannel may be about 8 feet, and the height (h) of the channel may beabout 1 foot. It should be noted that the figures are not necessarilyproportional or to scale. The conduit may be modified to be up to 5 feetin height (h), 10 feet wide (w), and of unlimited length (l). In anotherembodiment, the dosing pipes 116, 120, 124 may be replaced with a lowaspect ratio conduit 20, comprising a low aspect ratio channel 24, withthe low aspect ratio channel 24 adjacent to each of the “U” shapedgeonet volumes 128. Thus water may be applied to the dosing pipe 22, andthe low aspect ratio channel 24 would provide fluid communication to allthe “U” shaped geonet volumes 128. Additionally, in another embodiment,the “U” shaped volumes may be constructed out of pieces about half aslong, that simply lay adjacent to the geonet 40. The conduit 108comprises channels that are coincident with the “U” shaped volumes 128and rectangular volume 112.

FIG. 17 shows a top view of the high aspect conduit 108 from FIG. 16.The irregularly coiled stringy structures 44 that make up the geonet 40are not shown in this Figure in order to simplify the Figure for betterunderstanding. Additionally, each of the dosing pipes 116, 120, 124 arecovered with an air and water permeable sheeting (not shown in this viewfor ease of understanding), and each of the geonet volumes 112, and 128are enclosed in an air and water permeable sheeting (not shown in thisview for ease of understanding).

FIG. 18 is a front cross-sectional view of the conduit 108 from FIGS. 16and 17, through the plane B-B (shown in FIG. 17). In this view, each ofthe perforated dosing pipes 116, 120, 124 are shown wrapped in an airand water permeable sheeting 48. The generally rectangular volume 112 isshown with the irregularly coiled stringy structure 44 that makes up thegeonet 40. The “U” shaped volumes 128 are shown also with the shown withthe irregularly coiled stringy structure 44 that makes up the geonet 40visible. The volumes 112, 128, are enclosed in an air and waterpermeable sheeting 48.

The wastewater conduits shown in FIGS. 13-18 may be easily installed ifa roll of geonet is used. Geonet is often sold in rolls of varioussizes, from about half a foot in width, and about half an inch inthickness, and up to lengths of about 450 feet or more. Thus, one methodof installing a wastewater conduit as shown in FIG. 13, is to obtain ageonet of about one inch in thickness, and about 1 foot in width, andabout 8 feet in length. The 8 foot geonet is covered in an air permeablesheeting on all sides except for the top of the geonet which will beadjacent to a perforated dosing pipe. An 8 foot in length dosing pipe ofabout 1″ outer diameter may then be attached to the 8 foot geonet bywrapping the pipe with an air permeable sheeting and attaching that airpermeable sheeting to the sheeting around the geonet. A trench may bedug about 8-12 inches deep and 8 feet long and about 2 inches wide. Thedosing pipe and geonet may then be placed in trench and the trenchfilled in with soil, sand, or what ever material is suitable. The dosingpipe may then be coupled to the outflow of wastewater from the residenceor business. Conduits may also be about 12 inches high by about 1 inchwide, with length varying depending on the size of land available. Itshould be noted that “U” shaped volumes may be easily formed by simplybending the geonet into the desired shape.

The dosing pipe 22 may be configured to allow fluid such as waste waterto flow into the geonet in a manner similar to that described in U.S.Pat. No. 6,959,882 issued on Nov. 1, 2005 to David A. Potts and entitled“Watering and aerating soil with a drip line”, wherein instead offlowing the fluid into soil, the fluid is flowed into the geonet. U.S.Pat. No. 6,959,882 is fully incorporated in its entirety by referenceherein.

FIG. 19 is a top view of the disclosed high aspect ratio conduit 136.This high aspect ratio conduit 136 comprises a perforated dosing pipe22, a geonet layer 140 laying below and in fluid communication with thepipe 22. The geonet layer 140 comprises a geonet 40 that is about 4inches in thickness “t”, as shown in FIG. 20. It should be noted that inother embodiments, the geonet layer 140 may be replaced with pea stone,crushed stone, plastic pieces or other granular or permeable media.Laying below the geonet layer 140 are a plurality of geonet volumes 144.Each geonet volume 144 comprises a volume of geonet 40 enclosed in anair and water permeable sheeting 48. Please note that the coiled stringystructures of the geonet 40 are not visible due to the air and waterpermeable sheeting 48. The geonet layer 140 is shown partially cut-awayto reveal the geonet volumes 144 below. The width “w” of each geonetvolume may be about 1 inch. The distance “B” between each geonet volumemay be about 2 inches and up to about 10 feet or more apart. In thisembodiment the dosing pipe may have internal diameter of about 4 inches.The depth “D” of each geonet volume 144 may be about 12 inches, see FIG.20.

FIG. 20 shows a side view of the disclosed high aspect ratio conduit136. The thickness “t” of the geonet layer 140, the depth “D” of eachgeonet volume is shown, the width “w” of each geonet volume, and thedistance “D” between each geonet volume 140 are all shown. Theperforations 30 in the dosing pipe 22 may be generally aligned with thegeonet volumes 144. However in other embodiments, the perforations 30need not be aligned with the geonet volumes 144.

FIG. 21 is a perspective view of a conduit form 148 and conduit formcover 152. The conduit form 148 is configured to help install a highaspect ratio conduit 136 easily and quickly in the ground. With certainsoils, such as cohesive soils, simple trenching equipment may besufficient. The top and bottom 156 of the conduit form 152 are open.FIG. 22 is top view of the form 148, and FIG. 23 is a side view of theform 148. Referring now to FIG. 22, a volume 161 is defined by firstendwall 180, a front wall 220, a rear wall 216, a first interior wall188, an imaginary plane 184 through the an through the top surface ofthe form 148, and an imaginary plane 212 through the bottom of theinterior walls 188, 192, 196, 200, and 204. A volume 162 is defined byinterior wall 192, the front wall 220, the rear wall 216, an interiorwall 196, the imaginary plane 184 through the an through the top surfaceof the form 148, and the imaginary plane 212 through the bottom of theinterior walls 188, 192, 196, 200, and 204. A volume 163 is defined byinterior wall 200, the front wall 220, the rear wall 216, the interiorwall 204, the imaginary plane 184 through the an through the top surfaceof the form 148, and the imaginary plane 212 through the bottom of theinterior walls 188, 192, 196, 200, and 204. Volumes 161, 162, 163 areeach configured to contain a geonet volume 140. A volume 165 is definedby the interior wall 188, the front wall 220, the rear wall 216, theinterior wall 192, the imaginary plane 184 through the top surface ofthe form 148, and an imaginary plane 216 through the bottom surface 217of the form 148. A volume 166 is defined by the interior wall 196, thefront wall 220, the rear wall 216, the interior wall 200, the imaginaryplane 184 through the top surface of the form 148, and the imaginaryplane 216 through the bottom surface 217 of the form 148. A volume 167is defined by the interior wall 204, the front wall 220, the rear wall216, the end wall 208, the imaginary plane 184 through the top surfaceof the form 148, and the imaginary plane 216 through the bottom surface217 of the form 148. Volumes 165, 166, and 167 are configured to holdthe soil or sand or any other suitable granular material that willoccupy the volumes between the geonet volumes 140. It should be notedthat the geonet can be substituted with other granular material andplaced in volume 165, 166 and 167. In one embodiment, the height “D₁” ofthe volumes 165, 166 and 167 is greater than the height “D₂” of thevolumes 161, 162, and 163. The form 148 also has a plurality of liftingmembers 168. The lifting members may be lifting hoops as shown in FIG.21, or any other lifting mechanism configured to allow one to lift theform 148 out of the ground. The volumes 161, 162, and 163 have a widththat is generally “w”, which is generally the same as the width of eachgeonet volume described with respect to FIGS. 19 and 20. Similarly, thevolumes 165, 166, and 167 have a width that is generally “B, which isgenerally the same as the width of the granular material, such as soilor sand, which occupies the volumes between the geonet volumes 144. Thevolumes 165, 166, 167 between the geonet volumes will be referred toherein as granular volumes. Additional forms and trench shoring devicescan be utilized to maintain the integrity of the excavation and to placeadditional sand, soil or media around the form.

Referring back to FIG. 21, the form cover 152 has openings 172corresponding to the volumes 165, 166 and 167. Additionally, the formcover 152 has a plurality of lifting members 176. The lifting membersmay be lifting hoops as shown in FIG. 21, or any other lifting mechanismconfigured to allow one to lift the form cover 152 off of the form 148.One method of using the form 148 and cover 152 to make a high aspectratio conduit is as follows: dig a trench in the ground that canaccommodate the form 148 and cover 152, fill the volumes 165, 166, and167 with soil, or sand. Once filled, remove the cover 152, fill theopenings volumes 161, 162 and 163 with a geonet. Finally, remove theform 148. At this point, a geonet layer 140 is placed on top of thegeonet volumes and the sand/soil volumes. Next a perforated dosing pipe22 is laid on top of the geonet layer 140 and covered with a geotextilefabric or other material. Then, a layer if soil or sand is placed overthe high aspect ratio conduit. Although three volumes 161, 162, 163 andthree granular volumes 165, 166, 167 are shown, more or fewer volumesmay be used depending on how many geonet volumes 144 and granularvolumes are needed for a particular high aspect ratio conduit. Ofcourse, the form cover 152 will be configured to have openings 172corresponding to the granular volumes. The form cover may alsoincorporate a funnel, hopper, etc. into the device to improveconstruction efficiencies.

FIG. 24 shows a cross-sectional view of another embodiment of thedisclosed conduit. In this figure, the high aspect ratio conduit 224comprise a plurality of channels 228, 232, 236. Each channel is agenerally rectangular volume, within which is a geonet 40. Theirregularly coiled stringy structure 44 that makes up the geonet 40 isshown in this view. Each geonet 40 is enclosed in an air and waterpermeable sheeting 48. One or more dosing pipes 22 will be in fluidcommunication with the channels. A low aspect ratio conduit can besubstituted for dosing pipe 22. Additionally, there are a plurality ofpairs of anchors 240, attached to the permeable sheeting on adjacentchannels. Each pair of anchors 240 is attached to a line 244. Theanchors 240 and lines 244 are configured to allow the channels 228, 232,236 to be spaced a predetermined amount in the ground to facilitate thebackfilling of the volumes between adjacent channels 228, 232, 236 withsand, or other backfill. However since the lines 244 are attached toadjacent channels, the channels 228, 232, 236 may be collapsed (i.e. setclose together) for shipping. The anchors 240 may be any suitableattaching device, including but not limited to staples, plastic staples,washers. The lines 244 may be any suitable line, including but notlimited to nylon line, rope, twine, chain link. To install the disclosedconduit 224, the channels 228, 232, 236 are expanded to the maximumseparation distance between them, given the length of the lines 244.Stakes are typically driven into the soil to prevent the conduits frommoving around in the trench and to keep them at the desired distanceapart as determined by the lines 244. Although three channels 228, 232,236 are shown in the embodiment, one of ordinary skill will understandthat this conduit may be modified to have fewer channels, or morechannels, such as 10 or more channels.

In use, the disclosed high aspect ratio channels will be periodicallydosed with wastewater so as to fill conduit and displace gas. As thewastewater drains out of the high aspect ratio channels, air is pulledin “behind” the wastewater. Additionally, the system may be configuredto fully drain the high aspect ratio channels between doses. This helpsmaintain aerobic conditions in the conduit and helps oxidize thesludge/biomat. Prior art devices are designed to provide storage volumefor water in the channels. This storing or water in the conduit resultsin the persistence of anaerobic conditions at the soil interface andsubsequent organic buildup and less favorable conditions for treatment.Thus the current invention may configured to fill about 25 to about 100%of the channel void space per dose and allowing the channel to largelydrain before the next dose. Preferably, the time between dosing willabout two times the time for a dose of water to percolate into the soil.It is conceived that that will better enable the high aspect channel andrecently-saturated soil near the high aspect channel to drain of water,and to refill with gas, which is in good part oxygen containing air,flowing downward through the soil and through the permeable top of theconduit. If air distribution pipes are connected to vents, the foregoingeffect can be enhanced by suitable valving at the inlet end of the pipeor pipes, through the use of check valves on the vent lines, whichvalves will close when water is applied to the conduit. When the waterpercolates into the soil, it allows the check valve or similarfunctioning device to open and provide for the flow of air to replace anequal volume of water. With the high aspect ratio channels, thesidewalls will likely play more of a role in water draining than in thelow aspect ratio conduits. Additionally, a larger water column due tothe geometry of the channels will assist in the infiltration of gasesinto the channels as the water drains out of the channels.

The disclosed high aspect ratio channels will have an infiltration areato storage volume ratio of about 9 or greater. The infiltration area tostorage volume ratio is calculated as follows: for a channel that is 1foot high, 3 inches (0.25 feet) wide, and 10 feet long, the maximumstorage volume of that channel is given by 1 foot×0.25 feet×10 feet,which is 2.5 ft³. The infiltration area is given by adding together thesurface areas of the left and right side of the conduit and the bottomof the conduit. The left side of the conduit is given by: 1 foot×10 feetwhich equals 10 ft². The right side of the conduit is given by: 1foot×10 feet which equals 10 ft². The bottom of the conduit is given by0.25 feet×10 feet which equals 2.5 ft². Adding them together gives 22.5ft². The infiltration area to storage volume ratio is therefore 22.5ft²÷2.5 ft³=9 ft⁻¹. The front and rear surface areas of the conduit wereignored because we are omitting surfaces at opposing angles, andparallel surfaces closer than about 4 inches apart. The logic for thisis that saturated soils can result in proximity to infiltrative surfacesso close together, and gas movement in these regions is inhibited, whichmay lead to less aerobic conditions that desired. The disclosed conduitswill have widths greater than about ½ inch.

It should be noted that the terms “first”, “second”, and “third”, andthe like may be used herein to modify elements performing similar and/oranalogous functions. These modifiers do not imply a spatial, sequential,or hierarchical order to the modified elements unless specificallystated.

While the disclosure has been described with reference to severalembodiments, it will be understood by those skilled in the art thatvarious changes may be made and equivalents may be substituted forelements thereof without departing from the scope of the disclosure. Inaddition, many modifications may be made to adapt a particular situationor material to the teachings of the disclosure without departing fromthe essential scope thereof. Therefore, it is intended that thedisclosure not be limited to the particular embodiments disclosed as thebest mode contemplated for carrying out this disclosure, but that thedisclosure will include all embodiments falling within the scope of theappended claims.

1. A leaching conduit comprising: a channel; a first pipe in fluidcommunication with the high aspect ratio channel; the channelcomprising: a first geonet of a first height located below and in fluidcommunication with the first pipe, and laying in generally a rectangularplane along a length of the first pipe; at least one second geonet of afirst height, formed into a generally U-shaped configuration, with abottom of the U laying adjacent to the first geonet, and the at leastone second geonet located below and in fluid communication with thefirst pipe; at least one third geonet of a first height, formed into agenerally U-shaped configuration, with a bottom of the U laying adjacentto the first geonet, and the at least one third geonet located below andin fluid communication with the first pipe; and wherein the aspect ratioof each geonet is between about 96 and
 3. 2. The leaching conduit ofclaim 1, wherein each of the geonets are at least partially enclosed inair and water permeable sheeting.
 3. The leaching conduit of claim 1,wherein each of the geonets are at least partially enclosed in air andwater permeable sheeting.
 4. A wastewater system comprising: aprocessing tank; a leaching conduit in fluid communication with a dosingdevice; wherein the leaching conduit comprises: a channel; a dosing pipein fluid communication with the channel; a first geonet of a firstheight located below and in fluid communication with the dosing pipe,and laying in generally a rectangular plane along a length of the dosingpipe; at least one second geonet of a first height, formed into agenerally u-shaped configuration, with a bottom of the u laying adjacentto the first geonet, and the at least one second geonet located belowand in fluid communication with the dosing pipe; and at least one thirdgeonet of a first height, formed into a generally u-shapedconfiguration, with a bottom of the u laying adjacent to the firstgeonet, and the at least one third geonet located below and in fluidcommunication with the dosing pipe; and wherein the aspect ratio of eachgeonet is between about 96 and
 3. 5. The wastewater system of claim 4,wherein each of the geonets are enclosed in air permeable sheeting.
 6. Aleaching conduit comprising: a channel; a first pipe in fluidcommunication with the high aspect ratio channel; and the channelcomprising: at least one first geonet of a first height, formed into agenerally U-shaped configuration, with a bottom of the U layinggenerally parallel to the first pipe, and the at least one first geonetin fluid communication with the first pipe; at least one second geonetof a first height, formed into a generally U-shaped configuration, witha bottom of the U laying adjacent to bottom of the U of the at least onefirst geonet, and the at least one second geonet in fluid communicationwith the first pipe; and wherein the aspect ratio of each geonet isbetween about 96 and about
 3. 7. The leaching conduit of claim 6,wherein each geonet is about 1 inch to about 6 inches thick.
 8. Theleaching conduit of claim 6, further comprising: a granular medialocated generally on the sides, bottom of the channel.
 9. The leachingconduit of claim 8, further comprising: a granular media located on thetop of the channel.
 10. The leaching conduit of claim 8, wherein thegranular media is selected from the group consisting of sand, soil, andplastic beads.
 11. The leaching conduit of claim 6, wherein the firstpipe is located above the channel.
 12. The leaching conduit of claim 6,wherein each geonet comprises the material selected from the groupconsisting of an irregularly coiled stringy structure with one layer ofan air-permeable sheeting; an irregularly coiled stringy structurecontained between two layers of an air-permeable sheeting; crushedstone; pea stone; polystyrene aggregate incorporated into suitablenetting; polystyrene aggregate incorporated into suitable blanket; and amolded plastic three dimensional grid.